How to Interpret the AFUE Rating on a Heater

When fall begins in White Plains, NY, prudent homeowners turn their attention to their heating systems. In the event that a heater has become too worn to function properly for another winter, a replacement must be chosen and installed. Now makes an excellent time of the year to do so, before cool temperatures take over for the entire winter. It gives the homeowner a chance to evaluate all of the options and plan a replacement at relative leisure.

Among the factors to keep in mind when selecting a new heater is the AFUE rating, which stands for Annual Fuel Utilization Efficiency. It is a means of gauging the efficiency of the heating system, and can be used to find the furnace best suited to a specific home.

The rating is derived via a simple formula: dividing the energy required to run the furnace (in BTUs or British Thermal Units) with the heating energy the system releases (also in BTUs). This registers as a percentage: the higher the percentage, the more of the heater’s consumed energy gets released as heat into the home (the rest being lost to exhaust and inefficiency). So a furnace with an AFUE rating of 80% would lose 20% of its consumed energy to waste, while a furnace with an AFUE rating of 90% loses only 10% of its consumed energy to waste.

The system loses efficiency the older it gets, and if possible, a replacement furnace should always have a higher AFUE rating than the older furnace it is replacing. That means that the new heater—assuming its overall power levels are identical to the old one—will function more effectively, and that means lower monthly bills that can help recoup the cost of installing the system.

The experts at Yost and Campbell Heating, Cooling and Generators can install a new furnace this fall.